You never know what'll wash up in San Diego Creek near Irvine. An old sneaker. A gnarled piece of oak tree. A Union cannonball from the Civil War.

It's truer than the Confederate flags dangling from OC bro trucks: a cannonball that's said to date back to the U.S. Civil War was discovered in the San Diego Creek bed by a hiker recently.

"It's a real cannonball, it is really a live round," Orange-based historian Douglas Westfall told KCBS2. "It is four inches in diameter, weighs about like a 10-pound bag of sugar, so it is quite heavy."

It's got Westfall and other historians scratching their heads. "It was always just a cornfield," he said of the area where the discovery was made. "Prior to the Civil War, the only cannonballs that would have been used in California would have been during the Mexican-American War. The Mexicans never made cannonballs."

Other than in the pools they just cleaned. ... Sorry, Gustavo, I'll show myself out.

Westfall received the cannonball from the hiker before turning it over to the Lincoln Memorial Shrine in Redlands. But he's continuing to investigate how it went up a creek. (Or "crick," to those who received Union fire.)

One theory: Union soldiers literally dropped the ball while marching toward the coastline to thwart landings by Confederates, who had many Southern California sympathizers during the war between the states.

(Not to be confused with those dangling stars and bars from OC bro trucks.)

Matt Coker has been engaging, enraging and entertaining readers of newspapers, magazines and websites for decades. He spent the first 13 years of his career in journalism at daily newspapers before "graduating" to OC Weekly in 1995 as the paper's first calendar editor. He has contributed as a freelance editor and writer to several publications and been the subject of or featured in several reports online, in print and on the radio and television. One of countless times he returned to his Costa Mesa, CA, home with a bounty of awards from a journalism competition, his wife told him to take out the trash.